Method and apparatus for hydrocarbon conversion



Oct. 21,1947. E. v. BERGSTROM METHOD AND APPARATUSVFOR HYDROCARBON CONVERSION Filed Sept. 20, 1946 2 Sheets-Sheet 1 PRODUCT RECOVER Y INVENTOR .mvc 4 5RG677FOM ANT OR ATTORNEY Oct. 21, 1947- E. v. BERGSTROM METHOD AND APPARATUS FOR HYDROCARBON CONVERSION Filed Sept. 20, 1946 2 Sheets-Sheet? INVENTOR ER/ C V. 5ER65770M Q. AGENToR ATTORNEY Patented Oct. 21, 1947 t UNITED STATES PATENT OFFICE METHOD AND APPARATUS FOR HYDRO- CARBON CONVERSION Eric V. Bergstrom, Short Hills, N. J., assignor to Socony-Vacuum Oil Company, Incorporated, a corporation of New York Application September 20, 1946, Serial No. 598,379

10 Claims. (Cl. 196-52) l 2 This invention has to do with a method and materials such as mullite, zirkite, or a refractory pp rat s for conversion of fluid hydrocarbons material containing about 70% alumina and the in the presence of a particle-form solid contact remainder largely silica. In order to'permit pracmaterial which may or may not be catalytic in tical rates of gas flow through the contact matenature. 5 rial which i maintained as a substantially com- Exemplary of the processes to which this inpact column in the conversion zone, the contact vention may be applied are the catalytic cracking material should be made up of particles falling conversion of high boiling fluid hydrocarbons, the within the size range of about 3 to 100 mesh and catalytic hydrogenation, dehydrogenation, aropreferably! to 20 mesh by Tyler standard screen matization, polymerization, alkylation, isomerizaanalysis. tion, reforming, treating or desulfurizing of se- In such processes wherein the direction of gas lected hydrocarbon fractions. Also exemplary fiow' through the reaction zone is countercurrent are the thermal cracking, viscosity breaking and to the downward flow of the contact material, the coking of hydrocarbon fractions in the presence maximum rate of gas flow should be limited to of heated inert, solid materials. that which will not cause "boiling of the contact Typical of such processes is the catalytic crackmaterial or serious interference with its flow, ing conversion of hydrocarbons, it being well otherwise, serious difficulties arise such as chanknown that high boiling fluid hydrocarbons may neling of the solid and gas flow and excessive be converted to lower boilin gaseous. gasoline attrition of the solid material. In many proccontaining hydrocarbon products by exposure to esses such as, for example, the conversion of liqa suitable adsorbent type catalytic material at uid hydrocarbons to lower boiling gaseous prodtemperatures of the order of about 800 F. and ucts, it is desirable to pass the reactant fluid higher and at pressures usually above atmosdownwardly through the conversion'zone concurpheric. Such a process has recently been develrently with the'contact material flow. In such oped commercially into a continuous cyclic proc- 5 processes a serious difficulty arises in the withess wherein the solid catalyst is passed cyclically drawal of gaseous reactants from the contact through a conversion zone wherein it is contacted material column within the conversion zone. In

with fluid hydrocarbons to eilect the conversion one form of operation practiced heretofore a row thereof and through a regeneration zone wherein of inverted, spaced, collecting troughs was posiitis contacted with a combustion supporting gas tioned in the column of contact material within such as air which acts to burn off from the catthe lower section of the reactor and gas was withalyst a carbonaceous contaminant deposited drawn through suitable pipes extending under the thereon in the conversion zone, ends of the troughs. Such an arrangement is This invention is particularly concerned with unsatisfactory due to serious entrainment of consuch cyclic conversion processes or gas-solid con- 5 tact material in the gaseous streams withdrawn l tacting processes wherein the particle-form confrom the ends of the collecting troughs. This tact material moves through the conversion zone entrainment is no doubt partially due to the or contacting zone-as a substantially compact col limited settling space available for settling out umn and wherein gaseous reaction products of of entrained particles under the collecting contacting gas and the used contact material are 40 troughs. It may be further due to the fact that separately withdrawn from the conversion or the static pressure under each collecting trough contacting zone. progressively increases-along its length with dis- In such cyclic processes wherein the contact tance from the gas withdrawal point so as to material is a catalyst it may partake of the nacause a maximum rate of gas disengagement from ture of natural or treated clays, bauxite, inert the solid surface and ofsolid entrainment along carriers upon which catalytic materials such as that portion of the lengths of the collecting metallic oxides have been deposited or certain troughs nearest the end of gas withdrawal theresynthetic associations of silica, alumina, or silica from.

and alumina to which small amounts of other A major object of this invention is the provimaterials such as metallic oxides may be added sion in a process wherein a gaseous material is for special purposes. In processes wherein the contacted with a substantially compact column contact material is not catalytic in nature its of particle-form contact material of animproved purpose is usually that of a heat carrier and may method and apparatus for withdrawal of gas from take any of a number of forms, for example, said column without substantial entrainment of spheres or particles of metals, stones or refractory contact material particles.

flowing downwardly through said zone in the direction or the reactant flow, v

A specific object is the provision in a hydrocar- 23. An inert seal gas such as steam or flue gas may be admitted through conduit 2| into a seal zone maintained at the upper end of vessel II for the purpose of preventing hydrocarbon escape through the gravity feed leg. The rate of seal gas introduction may be so controlled by means of diaphragm actuated valve 22 and differential pressure control instrument 23 as to maintain a seal gas pressure in the seal zone slightly above bon conversion process wherein the contact mathe hydrocarbon pressure in the upper section of terial moves downwardly as a. substantially compact column of solid particles concurrently to the fluid reactant flow of a practical method and apparatus for withdrawal of gaseous conversion products from said column in the conversion zone .45

. without? substantial entrainment of contact material particles in the efliuent gas stream.

These and otherobiects of this invention will become apparent from the following detailed description of the invention. Before proceeding with the description, certain expressions employed herein in describing and in claiming this invention will be defined. The term gaseous" as used herein unless specifically otherwise modifled, is intended broadly to cover material existing in'the gaseous phase under the particular operating conditions involved regardless of what may be the normal phase of that material under ordinary atmospheric conditions. The expression contact materia unless otherwise specifically modified, is used herein in a broad sense to cover any. solid material having suitable heat carrying and stability properties for the particular process application in which it is employed, and the expression is intended to broadly cover catalytic and non-catalytic materials.

The invention may be most readily understood by reference to the drawings attached hereto of which Figure 1 is an elevational view of an arrangement 'of a cyclic conversion system to which this invention is applied;

Figure 2 is an elevational view, partially in section of a conversion vessel constructed according to this invention;

Figure 3 is a sectional plan view taken along line 3-3 of Figure 2.

All of these drawings are highly diagrammatic in form.

Turning now to Figure 1, there is shown a conversion vessel l D, a regeneration or reviviflcation vessel H and conveyors i2 and i3 for transfer of contact material between the conversion and regeneration vessels. In operation, particle-form contact material is supplied from hopper so through gravity feed leg 4| into the upper section of the conversion vessel Ill. Used contact material is withdrawn from the lower end of vessel It through drain conduit Hi. The rate of contact material flow is controlled by valve IS on conduit I4 so that a substantially compact column of contact material is maintained within the conversion zone. The hydrocarbon charge to vessel in may exist in the gaseous phase or liquid phase or both. The charge may be vaporized and/or heated and separated into vapor and liquid fractions in a suitable charge preparation system 16 which may be of conventional design. Heated charge vapors may be admitted to the upper section of the conversion zone through conduit l1 and heated liquid charge may be admitted through conduit l8. Gaseous conversion products are withdrawn separately of the contact material, from the lower section of the conversion zone through conduit l9 through which it passes to a conventional product recovery system the conversion zone. An inert purge gas such as steam or flue gas may be introduced into'the contact material column below the level of gaseous reactant withdrawal through conduit 24 for the purpose of purging gaseous reaction products from the outflowing used contact material. The

- used contact material is-transferred by conveyor I2, which may be a continuous bucket elevator for example, to the upper end of regeneration vessel II. The regeneration vessel shown is of the multi-stage type, well adapted for the regeneration of spent cracking catalysts. Air or oxygen containing gas is introduced from manifold 25 into several superposed burning stages through inlet conduits 26, 21 and 28. Flue gas may be withdrawn from these stages through conduits 29, and 3|, all connecting into outlet manifold 32. The contact material temperature may be controlled by passing a suitable cooling fluid through cooling tubes located in vessel ll between the burning stages. Cooling fluid may be introduced into the cooling tubes (not shown) through communicating inlets 33 and 34 and withdrawn therefrom through communicating outlets and 33. Regenerated contact material is withdrawn from vessel ll through drain conduit 31 through which it passes to conveyor Hi. The hot regenerated contact material is transferred by conveyor l3 to reactor supply hopper 40. While the regenerator described hereinabove is of the multi-stage type it will be understood that other types of regenerators adapted for regenerating contact materials may be employed within the scope of this invention. The type of regenerator or reviviflcation vessel to be employed will vary depending upon the particular process involved. Any apparatus adapted to condition the contact material to a state satisfactory for re-use in the particular conversion process involved is contemplated to be within the scope of this invention. It should be further understood that this invention is not considered as limited to any particular position arrangement of conversion and regeneration vessels or to the particular apparatus described herelnabove for contact material introduction into the conversion vessel.

The improvement of this invention as applied to the conversion vessel in is shown in Figure 2 wherein I0 is the conversion vessel having solid inlet 4| at its upper end and outlet 14 at its lower end. A partition 43 is positioned across the upper section of the vessel Hi to provide a seal chamber 54 in the upper end of vessel Ill. Contact material passes from seal chamber 44 onto the surface of the contact material column or bed 45 in the conversion chamber therebelow through unlformly distributed tubes 46 which depend from partition 43. The partition 43 and tubes 46 combine to provide a gas distribution space 41 above the contact material column in the conversion chamber. Vaporized hydrocarbons may be introduced into the gas space through conduit H. A plurality of conduits extend across the gas space 41, being closed on their ends within the gas spacen These conduits connect on their opposite ends intoa liquid feed manifold It. A plurality of spaced spray devices 10 depend from each of the conduits ll. These devices are adapted to direct a spray of liquidcharge onto the surface of bed 45. Other suitable means for introduction of liquid hydrocarbon charge may be substituted for the apparatus described, if desired. Across the lower section of the vessel It there is positioned a partition Bil from which depend a plurality of spaced tubes M which are substantially uniformly distributed with respect to the vessel horizontal cross-sectional area. The tubes ii communicate with the bed above partition 50 and terminate on their lower ends a spaced distance below partition til so as to provide a single gas collecting space 52 below the partition 50 and surrounding the tubes BI. is positioned across vessel It at a level substantially below the lower ends oi tubes so as to provide room for a bed of solid material 54 over the partition 53. A plurality of uniformly distributed tubes 65 depend from partition 53 for now of solid material from-the bed 58 onto the surface of another bed 55 a spaced distance below partition $3. The arrangement automatically provides a second gas space Bl in the vessel located below p ltion 53 and surrounding tubes 55. A conduit It connects through the shell of vessel It to communicate with the space 81. While partition 50 is shown as fiat and partition 83 as dished, both may be dished or flat as desired. Two more partitions 58 and 59 are positioned at spaced vertical intervals below partition 58. In partition til there are provided two spaced concentric rows of holes ti) and ti and in partition 59 there is provided one circular row of holes 82. Conduits may be positioned within each hole if desired. Thus conduits B3 depend from partition 58. The arrangement is such that a plurality of streams, uniformly distributed with respect to the vessel cross-sectional area are withdrawn from the bed 53. These streams are proportionately combined into a smaller number of streamspassing through holes 62 in partition 89 which streams are horizontally staggered between the streams thereabove. Finally the streams from partition 59 are merged into a single stream flowing from vessel in through conduit It. This arrangement insures substantially uniform-withdrawal of contact material from all portions of the horizontal cross-sectional area of bed 5b. In practice the number of partitions required may be two or more, increasing with increasing diameter of the vessel it. If desired, the tubes 65 depending from partition 53 may be so arranged that partition 53 also serves as the uppermost partition in the solid flow control system described. A plurality oi uniformly distributed vertical tubes l2 extend downwardly from the gas space 52 through partition 53 into the gas space B1. A convenient method to support these conduits is to weld or fasten them to the underside of partition til, as shown. In such a case. holes ii are provided in the tubes 12 to communicate their interiors with the gas space 52. In other arrangements the tubes 72 may merely terminate on their open upper ends in the gas space '52, other means suitable for supporting the tubes being provided. The tubes 12 are not rigidly fastened to partition 58 but slide through holes in the partition 63 which are sufllciently large to'permit for movement of the tubes under thermal expansion or contraction, but said holes fit closely enough around the tubes-to prevent A second partition 53.

solid flow into space II. If the tubes 12 are not rigidly fastened to partition I0, they may then be rigidly fastened to'partition 58. It will be understood that the tubes II. I! and 12 may be of any convenient cross-sectional shape and may be arranged on any of a number of patterns. The term tube as used in claiming the invention is intended in this broad sense. A pattern suitable for a circular vessel is shown in Figure 3, taken at line 3-3 of Figure 2. Identical elements bear the same numerals in Figures 2 and 3. Inasmuch as it is oi vital importance to this invention that the gas spaces 8? and Ill be single gas spaces, the tubes ii and 5-! should be of substantially less horizontal dimension in every direction than the vessel l0. In some modifications, however, the tubes I2 may be rectangular in shape and extend substantially across the vessel.

In operation contact material enters the seal chamber 44 through conduit ll and passes from the bottom of the seal chamber through tubes 46 onto the surface of the contact material column to in the conversion chamber. The contact material flows downwardly through an upper portion of the conversion chamber as a substantially compact bed or column of gravity flowing particles. The rate of solid flow is controlled by throttling by means of valve I! on the outlet M from vessel it. Contact material passes from the bottom of bed through tubes Bl onto bed 54. At the same time heated gaseous'hydrocarbon reactants are introduced to vessel It through conduit ll and/or liquid hydrocarbons are introduced via conduit i8, pipes 65 and spray devices it. The hydrocarbon reactants pass downwardly within the bed 45 to become converted to lower boiling gaseous products. The gaseous conversion products pass downwardly with and through the contact material streams in tubes 5!, and the gaseous material disengages from the solid material at the lower ends of tubes 5| and enters gas collecting space 52. A certain amount of contact material'is entrained by the gas into space 52. Most of the entrained material settles to bed 54, and that material which does not settle is carried by the gas stream through tubes 12 into the second gas space 51 wherein the entrained solids settle onto bed 56. The substantially solid-free gaseous conversion products are withdrawn from gas space 51 through conduit l9. Used contact material from bed 84 is shunted through gas space 51 in tubes 55 which deliver it onto bed 58. The solid material is then uniformly withdrawn from substantially all portions of the cross-sectional area of bed 58 in the manner described hereinabove.

By throttling the solid flow at valve It in drain conduit It continuity of substantially compact material body is maintained upwardly from the level of valve it through the entire length of vessel ill to inlet feed conduit ll at its top. Inert seal gas such as steam may be admitted through conduit 2| into seal chamber 44 and purge gas may be admitted through conduit 24 into the space below partition 58. The purge gas passes upwardly through tubes 83 and bed 56 to be withdrawn with the gaseous reactants through conduit I8.

By the provision of partition and tubes 5i at the bottom of the conversion zone a very simple and eflective device isprovided for disengagement of gas from solid particles. The arrangement described provides an exceptionally great amount of disengaging surface area all at substantially one level. However, in most concurgas fiow toward the outlet. This difference in static pressure would give rise to unequal rates of gas flow from the reaction zone through tubes 51, the fiow being higher in those tubes depending into the lowest pressure area in the space 52. As a result, very poor disengagement and excessive solid entrainment would occur at the lower ends of those tubes through which the gas fiow was highest. By the provision of plenum chamber 51 which is of substantial size and by passage of gas from space 52 into this chamber the entrained solids may be settled from the gas stream before its withdrawal from the reaction vessel. Moreover the tubes 12 communicating various portions of space 52 with the same plenum chamber 51 help to equalize the static pressure in all portions of space 52 thereby permitting better and more uniform gas-solid disengagement. In some modifications of the invention the lower ends of tubes 12 may be curved so as to admit gas horizontally into space 51 therebyimproving the solid settling. A bafileplate 81 may be positioned in front of the opening to conduit 19 so as to prevent direct fiow of gas from those tubes 12 nearest the outlet into the outlet. It is often desirable, especially in the case of vessels of very large diameter to provide several outlets such as i9 at spaced intervals around the gas space 51.

The method and apparatus of this invention may be employed in a wide variety of processes involving contact of gas with a. column of particle- 8 said tubes. The tubes 55 should also be of sumcient size and number to handle the maximum anticipated contact material flow and the plenum chamber 51 should be in general of substantially greater depth than space 52. The tubes 12 should be of sufilcient size and number to handle the maximum anticipated gas flow at a very low pressure drop, for example less than about 2 inches of water. As an example in a typical satisfactor conversion apparatus the tubes 5| extended to a 7 common level about 6 inches below partition 50,

locations in gas space 52 would arise due to the the partition 53 was about 30 inches below partltion 50, the tubes 55 extended to a level about two feet below partition 53 and the tubes 12 terminated about 1'7 inches below partition 53.

It should be understood that the particular details of apparatus construction and of operation and the examples of application of this invention given hereinabove are intended as exemplary uppermost bed, introducing fluid hydrocarbon form solid material. The invention is particularly applicable to catalytic processes for the cracking conversion of liquid or vaporous hydrocarbon charges or both. In general such hydrocarbon conversion operations are conducted under temperatures within the range about 800 F. to 1100 F., the higher temperatures being employed for liquid charging stocks. Low pressures of the order of 5 to 30 pounds per square inch are generally employed in the conversion zone for cracking conversions. The oil charge space velocity may vary from about 0.3 to 10.0 volumes of oil (measured as liquid at 60 F.) per hour per volume of catalyst column within the reaction zone. The catalyst to oil throughput ratio may vary within the range about 1 to 20 parts of catalyst per part of oil by weight. In general the reactant charge is preheated to a temperature of the order of 600 F.-900 F. and all or part of the heat required for the conversion may be carried into the conversion zone in the catalyst. It will be understood that the particular apparatus dimensions employed will vary depending upon the particular operation and operating conditions charge into the uppermost bed and passing the contact material and hydrocarbon charge downwardly in said uppermost bed to effect conversion of said charge to lower boiling gaseous hydrocarbons, withdrawing said gaseoushydrocarbons and used contact material from the bottom of said uppermost bed as a plurality of confined streams distributed across the horizontal cross-sectional area of said bed. directing said confined streams downwardly through the gas space over the next lower, intermediate bed and onto the surface of said intermediate bed, causing the gaseous products to disengage from the contact materialat the surface of said intermediate bed and passing the disengaged gaseous products along with any entrained contact material particles as a plurality of horizontally spaced confined streams downwardly from the gas space above said intermediate bed, through said intermediate bed into the gas space above the lowermost bed, withdrawing gaseous conversion products from said last named gas space, passing contact material from the bottom of said intermediate bed as a plurality of confined streams distributed over the horizontal cross-sectional area of said bed through said gas space over said lowermost bed and onto the surface of said lowermost bed and withdrawing used contact material substantially uniformly from all portions of the horizontal cross-sectional area of said lowermost bed while throttling the rate of contact material withdrawal so as to maintain substantial continuity of substantially compact contact material body throughout the entire length 01 said confined zone.

2. A method for conversion of fluid hydrocarbons to lower boiling gaseous hydrocarbon products in the presence of a moving particle-form contact material which method comprises: introducing particle-form contact material into the upper section of a confined elongated conversion zone at a suitable temperature for said hydrocarbon conversion, passing said contact ma- .confined elongated conversion zone at a suitable temperature for said hydrocarbon conversion, passing said contact material downwardly through an upper portion of said zone as a: substantially compact bed of downwardly flowing particles, withdrawing contact material from the lower end of said bed by subdividing the bed into a plurality of confined substantially compact, vertical streams spaced apart and distributed. substantially uniformly with respect the horizontal'crosssectional area of said confined conversion zone, the cumulative cross-sectional area of said streams being substantially less than the crosssectional area of said zone so as to provide a single gas collecting space within said zone around said streams, directing the flow of said confined streams onto the surface of a second substantially compact bed of said contact material maintained at a lower level in said zone, similarly withdrawing contact material from the lower end of said second bed by similarly subdividing thebed into a plurality of confined streams so as to provide a second gas space of substantial area around said last named streams, directing the flow of said last named streams onto the surface of a third bed maintained at a still lower level in said zone, withdrawing used contact material from said third bed at a controlled rate, introducing heated fluid hydrocarbons onto the upper section of said conversion zone, passing said fluid hydrocarbons downwardly within said first named bed to effect conversion of said fluid hydrocarbons to lower boiling gaseous hydrocarbons, passing said gaseous hydrocarbons from the lower end of said conversion zone downwardly through said confined streams of contact material passing to said second bed, disengaging said gaseous hydrocarbons from said streams at their lower ends and collecting the gas in said single gas collecting space above said second bed, passing said gaseous hydrocarbons and any entrained contact material particles downwardly from said gas collecting space and into said second gas space maintained above said third bed as a plurality of confined streams originating at a plurality of spaced points in said gas collecting space said points being substantially uniformly distributed across said gas collecting space, withdrawing gaseous conversion products from said last named gas space, introducing an inert purge gas into said third bed to purge gaseous hydrocarbons from the control material and maintaining an ,inert gaseous pressure in said seal zone.

6. An apparatus for conversion of fluid hydrocarbons in the presence of a substantially compact column of particle-form contact material which comprises: a substantially vertical vessel adapted to confine a gas under pressure, means to introduce particle-form contact material to the upper section of said vessel, means to introduce a fiuid hydrocarbon to the upper section of said vessel, a partition transversely positioned across said vessel within a, lower portion thereof, a plurality of uniformly spaced tubes depending from said partition, said conduits communicating with the space above said partition and terminating a spaced distance therebelow so as to provide a gas collecting space immediately below said partition from which gas space solid fiow from said column is excluded, a second partition across said vessel a spaced distance below the lower ends 12 of said conduits, a second plurality of spaced tubes depending from said second partition, said last named conduits communicating with the space above said second partition and terminating a spaced distance below said second partition, so as to provide a solid settling. gas space below said second partition, said last named tubes being of substantially greater length than the tubes depending from said first partition, means to withdraw contact material from the lower section of said vessel, means defining a plurality of confined passages for gas flow from a plurality of points in said gas collecting space to said solid settlinggas space, and means to withdraw gas from said solid settling gas space.

7. An improved apparatus for gas solid contacting which comprises: a substantially vertical, confined vessel adapted to confine a contacting gas under pressure, means to introduce particleform contact materialv into the upper section of said vessel, means to withdraw contact material from the lower end of said vessel, flow throttling means associated with said withdrawal means,

. means to introduce fluid reactants into said vessel,

a partition positioned transversely across said vessel intermediate its ends, a plurality of uniformly distributed-tubes depending from said partition adapted for flow of material from above said partition to a level in said vessel spaced below said partition, a second partition across said vessel a spaced distance below the lower ends of. said tubes, a plurality of uniformly distributed tubes depending from said second partition adapted for fiow of solid material from above said second partition to a level in said vessel a spaced distance below said second partition, conduit means communicating a location in said vessel below said first partition and above the lower ends of the tubes depending therefrom with a location within said vessel below said second partition and above the lower ends of I the tubes depending therefrom and conduit means communicating the interior of said vessel at a level below said second partition and above the lower ends of the tubes depending therefrom with a location exterior of said vessel. I

8. An improved apparatus for gas solid contacting which comprises: a substantially vertical, confined vessel adapted to confine a contacting gas under pressure, means to introduce particleform contact material into the upper section of said vessel, means to withdraw contact material from the lower end of said vessel, flow throttling means associated with said withdrawal means, means to introduce fluid reactants into said vessel, a partition positioned transversely across said 'vessel intermediate its ends, a plurality of uniformly distributed tubes depending from said partition adapted for flow of material from above said partition to a level in said vessel spaced below said partition, a second partition positioned transversely across said vessel a spaced distance the space within said vessel below said first partition and above the lower ends of the tubes depending therefrom and on their open lower ends with the space below said second partition but the cumulative cross-sectional area of said components being substantially less than the crosssectional area of said zone so as to provide a single gas collecting space within said zone around said components having a substantial horizontal cross-sectional area, directing the flow or said confined components onto the surface of a second substantially compact bed of said contact material maintained at a lower level in said zone, similarly withdrawing contact material from the lower end of said second bed by similarly subdividing the bed into a plurality of confined components so as to provide a second gas space of substantial size around said last named components, directing the fiow of said last named components onto the surface of a third bed maintained at a still lower level in said zone, withdrawing used contact material from said third bed at a controlled rate, introducing heated fiuid hydrocarbons onto the upper section of said conversion zone, passing said fluid hydrocarbons downwardly within said first named bed to effect conversion of said fluid hydrocarbons to lower boiling gaseous hydrocarbons, passing said gaseous hydrocarbons along with said first named confined components onto the surface of said second bed, collecting said gaseous hydrocarbons in said gas collecting space over said second bed, passing said gasof a third bed maintained at a still lower level in said zone, withdrawing used contact material from said third bed substantially uniformly from all portions of its horizontal cross-sectional area while controlling the rate of such withdrawal such as to insure continuity of substantially compact contact material body from the level of contact material withdrawal from said third bed upwardly through said confined zone to the location of contact material introduction thereinto, introducing heated fluid hydrocarbons onto the upper section of said conversion 'zone, passing said fluid hydrocarbons downwardly within said first named bed to effect conversion of said fluid hydrocarbons to lower boiling gaseous hydrocarbons, passing said gaseous hydrocarbons along with said first named confined components onto the surface of said sec-.

ond bed, collecting said gaseous hydrocarbons in said gas collecting space over said second bed, passing said gaseous hydrocarbons and any entrained contact material particles separately of the main body of contact material as a' plurality of horizontally spaced, substantially vertical, confined streams passing through said second bed into said gas space above said third bed to allow settling of entrained particles onto said third bed and withdrawing gaseous conversion products from said last named gas space.

4. A method for conversion of fiuid hydrocarbons to lower boiling gaseous hydrocarbons in the presence of a moving particle-form solid contact material which comprises: passing pareous hydrocarbons and any entrained contact material particles separately of the .main body of contact material as a confined stream from said gas collecting space into said gas space above said third bed to allow settling of entrained particles onto said third bed and withdrawing gaseous conversion products from said last named gas space.

3. A method for conversion of fluid hydrocarbons to lower boiling gaseous hydrocarbon products in the presence of a moving particle-form contact material which method comprises: introducing particle-form contact material into the upper section of a confined elongated conversion zone at a suitable temperature for said hydrocarbon conversion, passing said contact material downwardly through an upper portion of said zone as a substantially compact bed of downwardly flowing particles, withdrawing contact material from the lower end of said bed by subdividing the bed into a plurality of confined components distributed uniformly across the horizontal cross-sectional area of said confined zone, the cumulative cross-sectional area of said components being substantially less than the cross-sectional area of said zone so as to provide a single gas collecting space within said zone around said components having a substantial horizontal cross-sectional area, directing the flow of said confined components onto the surface of a second substantially compact bed of said contact material maintained at a lower level in said zone, similarly withdrawing contact material from the lower end of said second bed by similarly subdividing the bed into a plurality of confined components so as to provide a second gas space of substantial size around said last named components, directing the flow of said last named components onto the surface ticle-form contact material at a suitable temperature for said hydrocarbon conversion downwardly through a confined conversion zone as a substantially compact column, introducing fiuld hydrocarbons into said zone and passing s'aid fiuid hydrocarbons downwardly within said column to effect the conversion thereof, withdrawing contact material from the lower section of said conversion zone as a plurality of substantially compact, confined streams uniformly distributed with respect to the horizontal cross-sectional area of said column and directing the flow of contact material from said confined streams onto the surface of a bed of said contact material maintained in the lower portion of a confined disengaging zone, passing gaseous conversion products through said streams from the lower section of said conversion zone into said disengaging zone and collecting gaseous products in a gas space maintained above said bed in said disengaging zone, withdrawing contact material from the lower section of said bed in said disengaging zone as a plurality of confined substantially compact streams uniformly'distributed with respect the horizontal cross-sectional area of said bed and directing the fiow of contact material from said last named streams onto the surface of a bed of said contact material maintained below a gas space for solid settling in a third confined zone, said gas space being substantially larger than said gas space in said disengaging zone, withdrawing contact material uniformly from said third zone at a controlled rate, passing the gas from said gas space in said disengaging zone into said gas settling space in said third zone as a plurality of confined streams emanating from a plurality of points distributed across the cross-sectional area of said gas space in said disengaging zone and withdrawing gaseous conversion products from said gas space in said third zone.

5. A method for conversion of fiuid hydrocar- 7 bons to lower boiling gaseous hydrocarbon prod- 13 above the lower ends the tubes depending therefrom, at least one conduit for gas withdrawal connected through the shell of said vessel at a level below said second partition and above the lower ends of the tubes depending therefrom.

9. An apparatus for conversion of fluid hydrocarbons t lower boiling gaseous products comprising in combination: means defining an elongated, upright, confined conversion chamber, means defining a seal chamber above said conversion chamber, means to supply fresh contact material to said seal chamber, means to introduce an inert seal gas into said seal chamber, conduit means for flow of'contact material from the bottom of said seal chamber to a level within said conversion chamber below its upper end, means to introduce fluid hydrocarbon reactant into the upper section of said conversion chamber, means defining a disengaging chamber below said conversion chamber, a plurality of conduits for gas and solid flow extending from the bottom of said conversion chamber and terminatingwithin said disengaging chamber a spaced distance below the upper end thereof, said conduits being uniformly distributed across the bottom of said conversion chamber, means defining a third chamber below said disengaging chamber, a plurality of uniformly distributed conduits for solid flow extending downwardly from the bottom of said disengaging chamber and terminating within said third chamber a spaced distance below its upper end, a plurality of tubes for gas fiow extending from a level within the upper section of said disengaging chamber to a level withinthe upper section of said third chamber, means to withdraw gas from the upper section of said third chamber and means to withdraw solid material from the lower end of said third chamber.

10. In a gas solid contacting vessel wherein a gaseous material is contacted with a substantially compact column of particle-form solid contact material the improved apparatus for substantially separate withdrawal of gaseous material from said column which comprises in combination: a partition extending transversely across said vessel at a level intermediate its ends, said partition having a plurality of openings therein substantially uniformly distributed across the cross-sectional area of said vessel, said openings being 01' r 14 less horizontal dimension in ever direction than said vessel, a tube tightly fitted in each of said openings, said tube being open on its upper end to communicate with the portion of the vessel above said partition and terminating on its open lower end a spaced distance below said partition so as to provide a. single gas collecting space below said partition and around said tubes from which space gravity flow of solid from said column of contact material in said vessel is excluded, a second partition positioned across said vessel a spaced distance below the lower ends of said tubes, said partition also having a plurality of uniformly distributed openings therein, a tube tightly fastened into each of said openings in said second partition said tube being open on its upper end to 'communicate with the portion of the vessel above said partition and terminating on its open lower end a spaced distance below said second partition so as to provide a second singlegas space surrounding the tubes depending from said second partition, conduit means communicating said first gas space with said second gas space within said vessel, said conduit means being so positioned as to exclude gravity flow of solid thereinto, from said column and means to withdraw gas from said second gas space.

ERIC V. BERGSTROM.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,414,812 Houdry Jan, 28, 1947 1,422,007 Soddy July 4, 1922 2,327,175 Conn Aug. 17, 1943 2,364,453 Layng et al Dec. 5, 1944 2,410,309 Simpson et a1 Oct. 29, 1946 2,409,596 Simpson et a1. Oct. 15', 1946 2,386,846 Dunham Oct. 16, 1945 2,386,670 Evans Oct. 9, 1945 OTHER REFERENCES 8-page leaflet, Houdry Pioneer" of October 1946, vol, 2, No. 1. Published by Houdry Process Corp., 25 Broad Street, New York 4, N. Y. (Copy in Division 31.) 196-523. 

